Headlamps are used in a large number of activities, e.g. professional, sports and leisure.
In general, these lamps are designed to enable efficient and “hand-free” lighting, providing comfortable use with maximum battery life.
Patent application FR2930706 dated Apr. 24, 2008 describes a self-regulated lamp using a sensor for sensing the light reflected by an object illuminated by the lamp so as to allow the control of the brightness of the lamp. FIG. 1 illustrates such a prior art lamp that includes an optical sensor housed in the casing 14 in the vicinity of the light emitting diode LED 11 for generating a signal representative of the light reflected by the surface of an illuminated object 16, and for transmitting said signal to a second input of a control unit 13 to automatically control the power of the LED according to a predetermined threshold. In this way, an automatic regulation of the light beam emitted by the lamp is achieved without requiring any manual action for adapting the light to the environment, while managing energy consumption.
Thus, thanks to such a process, the light intensity varies according to the illuminated object, rising when the user's vision is distant and reducing the contrary in the case of near vision, especially when the light is focused on a object being “close” to the lamp.
This process significantly increases the comfort of the lamp as well as the battery life.
Nevertheless, new needs arise in the regulation of light intensity, which can not be satisfied with the aforementioned lamp.
Generally, it is desirable to have more sophisticated regulatory mechanisms that are likely to meet new expectations expressed by headlamps users, whatever their category: sports, military, professional, or simply “enlightened” amateurs.